Utilization of citrus and pineapple products in making resin compositions



Patented Aug. 16, 1949 PRODUCTS IN MAKING TIONS RESIN COMPOSI- "Oscar W. Schroeder, Los-Angeles, Califl, assignor of' twenty per cent to-William E. 'Beatty, Los Angeles, Calif., and three one-hundredthsto Belle A. Milnar, St. Paul, Minn.

, N Drawing. Application April 19, 1947,

Serial N01. 742,733 v The invention relates to thermo-setting plastic such as synthetic resin types of plastics viz., phenol formaldehyde resin, commonly called phenolics, alkyd type resin, commonly called glyptal, and the like. The invention relates to treatment of the liquid phase of such resins and more particularly to lowering the cost, delaying the polymerization during preconversion period to prevent setting during shipping or storage, hastenin polymerizing or curing during manu-.

facturing or conversion period, coloring, and de laying the curing action of a catalyst so that a quantity of resin, catalyst and dye stuff can be prepared for use over a period of time as a secondary color coat for interspersion with a base coat of a diiierent color.

One of the objects of the invention is to substantially cheapen the cost of liquid resin type plastic which has various industrial uses. This is accomplished by employin the natural raw, uncooked, undehydrated comminuted pulp of citrus fruits such as oranges, lemons, etc., also the leaves, hull or fruit of pineapple, or waste products thereof in their natural state, as a substantial part of the liquid plastic.

By pulp of citrus fruit is meant the skin,

rind and web, and perhaps the seeds, namely i everything that is left after one squeezes the juice out of the fruit, even though a small quantity of the juice itself can be used. One would suppose it would be impractical to use additives such as citrus pulp, or pineapple leaves (or 70% alcohol) to liquid resin for the reason that it is well known that they contain moisture and citrus pulp con- 'tains oil, moisture or oil being generally under- :stood as preventing the liquid resin from setting. The invention provides a process of making it possible to use such moisture containing additives by employing hydrochloric acid as a catalyst. Large quantities of citrus pulp are available and are commonly subjected to dehydration and sold for cattle food at a comparatively low price. It is unnecessary to dehydrate such pulp according to the present invention and hence, the pulp be- ,7 comes more valuable when used in the plastic as 'citrus pulp in it is stronger than such resin without the pulp, and the same is true of shredded pineapple rind, fruit and leaves.

It is believed that the citrus pulp is more than a filler, and that a chemical combination, as dis 13 Claims. (01. zen-17.2)

l tinguished from a mechanical mixture, results not only because of added strength but also for the following reasons. If 50% or more of an inert filler such as silica isadded to liquid phenolic and cast, the casting becomes granular and weak,

whereas up to 50% byvolume of citrus pulp does not impair, but increases the strength. 'As a second reason, the mix of pulp and liquid plastic turns an opaque milky color when the HCl is added, indicating a chemical reaction. As a third reason, when the citrus pulp is addedto the liquid resin, the usual amount viz. up to of the usual filler viz, walnutfiour or wood flour can also be used, even when using up to by volumeof the citrus pulp. Also, ten per cent by volume of methyl alcohol can be used as a 7 solvent or thinner;

On using citrus pulp as an additive, when the casting or coating sets it will be a uniiorm color,

or mottleddepending upon the fineness of the citrus pulp, assuming no added color material.

- If the skin and rind are grated with an ordinary household grater so that the comminuted pulp is rather coarse, the orange color of the skin disappears and instead the casting has the colorsome- What of pea soup with milk'added to it, mottled with small dark green specks in it, the specks can be eliminated and th casting made opaque milky white with no orange or green color, if

' about thirty parts liquid phenolic resin to about fiveparts of such HCl are used. If the pulp is finely divided for example, bypassing it through a screen having about thirty meshes to the linear inch, the casting is a uniform color, not mottled,

' if about thirty parts'of resin to five ofsuch HCl are used. To sum up the matter, the following are the reasons for believin that chemical action takes place, namely increased strength, the ability to use large quantities of the pulp without impairing the strength, the conversion of the pulp to a different color, and the fact that usual fillers can also be added. Infact, chemical combination appears to take place before. such HCl is Y added, as the pulp changes to a milky white color when stirred inliquid phenol formaldehyde resin.

The same reasons apply to pineapple leaf, rindor ,fruit. Equal parts of shredded pineapple and liquid phenol formaldehyde'resin have been used .with about 10%.ofsuchl-ICI. The. resin and'pineapple'are preheatedtoabout degrees F., then the acidis stirred iman'd' the mix will set in about 3 two hours at a temperature of about 90 degrees F. to 110 degrees F. The product is solid, milky white, and very tough.

The comminuted citrus pulpor pineapple leaf or rind. can be" stirred in the liqui'dresin and that mixture stored in bulk for days or weeks until ready for use. Such storing improves the break-- ing down of the pulp or the like into the resin. Liquid resin is commonlyiavaila-ble as a veryviscous fluid. If it is in transit orstoie'd fora month" or more, especially during hot weather, polymerization may set in to an extent making the'resin' rubber-like and useless. The orange; pulpor pineapple products will delay/this; premature curing,

' saucersha'd not. set at the endof ten" days.

A wide; range. of colonfor the liquid resin is obtained by adding thereto any one of the various dyes available: in powder form viz.,, aniline type such as the Eastenegg or clothing dye commonly available;,and by adding HClas a catalyst.

If the color of theplastic when set is to-besubstantially the same-asthat of the dye, the HCl 7 should first. be: mixed; withzthe liquidsynthetic resin, and aften a short delay; while the" mix is still viscousstir. in the cclor; If. the color is added to the. liquid; plasti beforer adding the HCl; the acid will bleach the dye, viz. a scarlet dye will-appear as a pink. color in the setplastic- This widens the range of, colcrs.-. Ineither case, the liquid resin is preferably preheated to about 90 degrees to 125 ;degrees Fl. and; either before or after adding; the HQI, the dye. stuff is added to g the, resin while .the resin is heated.

The advantageot reducing: the time required for the 1iquid resln.to.:set.o11 polymerize is obtained by. giving the-liquid resina: preliminary heat i.,e.,

. a preliminary polymerization treatment,;.insufiicient, however, tocauseit to seu;for example to from QO- d'egrees E. to l2 '5 degrees-F. and'by then adding} HCL as a. catalyst tothe heated resin whereupon theresin-hardens in a shorter time and without the necessity; for asubsequent curing heat treatment; although. curing, in! direct sunlight or at a temperature of about 90'degrees F. to 125 degrees E. is. preferred as. this reducesthe curingt time. I'ffcitruspulp, pineapple leafor the like is to be. used, iii-is?shredded,. grated, mashed or otherwisereducd'tc small-particles and mixed with the resin,'and the preliminary heat treatinent is given. tothatLmiiitu're of resin and additive..

Another. advantage oficui ingthe resinwith this mineral acidandimildhat-treatment is that a thicker. coating withlmore'body resultsthan if liquidlr'esin with weak organic acidviz. acetic were cured at an. erevated temperature. This is of advantage. for. coating. bricks. roughwood, metal, pasteboardor the Iiketo simulate stone, tile or solldl' las'tic.

If increased fi eiiibility. ofthesetplastic is desired, the 'liquid' resinmaybe 75%. or more of phenol fonnaldehyd'efres'im and or lessv of glypt'al, treatedaslaboye. v

The larger the al'nolliit OfZI-ICTthe more rapid is the evolutionv ofbu bbles and the faster the plastic will set. When used as an adhesive for two pieces of wood, about one inch square, thirty parts of liquid synthetic resin with or without the citrus pulp; to about fiveepartsl of HCl appear to-be: substantially completely settin about fifteen minutes although a strong bond results in less time, and without using artificial heat or pressure.

For translucent articles, use may be made of a catalyst partly" HCl, partly acetic acid viz. one part HCl, ten parts acetic acid to ten parts liquid resin. Mix acetic and heated liquid resin, later add HClwhileresin is still warm and if color is desired} powder aniline dye is added last, and stirred iii thew'ai'm resin. Also as catalyst, one canuse 1% to 3% HO] and no acetic acid. The I-ICl hastens the setting time, while giving a translucent end product.

The plastic of this invention may be used for any of the usual industrial purposes. When used for'molding,- one does not have tocontend with evolution of bubbles over a long' period of time, or use;hea-t to cure, especially if theliquid resin, with or without the citrus pulp, its-preheated for several minutes to degrees F. to 125 degrees F. and if a largeamountot I-ICl viz'l-about 15% to 20% is used. However, smaller amounts of I-ICl such as 5% andcuring' in direct sunlight or at temperatures'up to 125 degrees F. havebeen used and are preferred; The smaller the amount of acid and the lower the increase over 72- degrees F. for the resin the'longer thetime required to set, viz. 1%. HO and 'l 2 degrees F; curing may take four days. or more,- while=about--'5'% to 15% H01, with preheating the resin to about 100 degrees F and curing at about degrees F., the mixwill set=or hardenin about twohou-rs or less depending: on theadditives; The dye stuff, citrus pulp and pineapple delay; the curing. time.

All above references to Hql are to strong aqueous solution commonly called commercial grade HC1,and strongenough tofume. However, weaker acid canbe usedand is preferred when-using thel iquid resin as a-coatihg; composition for the reason that the action of thestrong acidis so rapid in acting on; the resin th ata; coating of liquid" resin and 5 to 20%;HCl will set with-- a rough. surface,.nota smooth-surface. A- smooth surface is usually preferredas it is: desirableto use. a thinner such 2'i. s' alcol'iol it is preferred to mix'the'strong'. acidwith the: alcohol and-add that miiitiire to the liquidresiin A For further details of the invention as applied to coating coihpositionare as follows. Assume it is desired to apply a plastic coat-t0 a wood letten for advertising. purposesgthe wood being rough riot sanded and-the color compi isinga groundicoat ofiohe colon interspersed with a pattemortonee more other colors.- ljust thewcod letter with'silicailour as thismalies theliquid stick better. the. wood base to about 100 degrees for teammate Mix liquid synthetic resin with aboiit'gl%i o'f glycerih and about 10% ct silica flour. andZprehat-foI:threeor four minutes toabout i'zc'aegr'ees Al-l percentsarewith reference to. the percentof volumeflof the liquid resin,. which is. preferably. pheholiormaldehyde.

While the abovemiiitur e is heated; stirin 1 0% of a mixture bf one parses. sti'bng, HCl and two parts l-of 'r'nethyllal'cohol (70 %l.proo f Whilethe mixture is still heated-or warm, :stir in-dyestuff such-as powderaniline dye -pf the desired: color. For white color, omit the -dye stufi and double the amountof silica-hour Apply 'witha brush or trowel to the; warm-wood base, or the base-can be dipped in the coating. For spraying the coat on the warm base use three parts alcohol with the acid instead of two parts.

Previously the secondary color or colors should be prepared with the above formula and allowed to stand for a few minutes until it starts to set as indicated by turning white around the margin whereupon about 25% methyl alcohol is stirred in. This will delay the setting of the secondary color, mix at the atmospheric temperature such as 90 degrees, for four or five hours so that this secondary color can be used over a period of time.

While the base coat is about to set but still soft to the touch, in a desired pattern, apply the secondary color mix by dropping it from a glass rod or the like on to the ground coat. Other secondary colors in other patterns can also be applied if desired. The ground coat and the outer coats merge to some extent and level off to a smooth top surface. Thus, red and White streaks or lines can be applied to a black or other solid color ground coat, the distinctive colors of the secondary coat or coats remaining in their true color without blending with the ground color. That is, the application of a white secondary pattern to a red ground color does not result in a cured article wherein the pattern is pink but instead the pattern retains its original color. It is believed that this is partly due to the fact that setting has started when the secondary color is applied; also, high curing temperatures are not required, as the coating composition above described can be cured in about one hour at 120'degrees F. The above coating composition when applied to a preheated base such as wood is set sufficiently on contact with the heated base so that it is viscous or lacking in fluidity to an extent such that the coating will not run off when applied to a vertical wall on the base, while giving a single coat sufficiently thick and opaque that saw cuts, knots, grain or defects in the wood are not visible through the coat.

When using HCl as a catalyst, it has been found that the coating composition above described has the tendency to form bubbles or pits at the surface of the cured article. This is overcome by being careful not to stir in air bubbles after the I-ICl has been added, that is, the color should be stirred in gently with a large glass rod. Also, after the coating or coatings have been applied to the base of wood, metal or other material, the coating is allowed to set at atmospheric temperature, preferably not over 90 degrees, for about one hour, until a smooth skin is formed on the coating, as this skin entraps and prevents release of any further bubbles at the surface, and then the coated article is cured as above described viz. 120 degrees F. for one hour.

Various modifications may be made in the invention without departing from the spirit of the following claims.

I claim:

1. The step in the process of utilizing citrus pulp which comprises comminuting said pulp and. mixing the oomminuted pulp with phenol formaldehyde resin in liquid phase.

2. The step according to claim 1 wherein the pulp which is mixed with said plastic is not dehydrated.

3. The step according to claim 2 and the additional step of mixing in the ratio of about thirty parts of the pulp and plastic mixture to about one part to five parts of hydrochloric acid.

4. The process of obtaining a mottled green color solid plastic from liquid amber color phenol formaldehyde resin and orange pulp which. comprises mixing said liquid resin and said pulp with hydrochloric acid in the proportion of about one part to three parts of acid to thirty parts of resin.

5. The process which comprises polymerizing a mixture of raw citrus pulp and liquid phenol formaldehyde resin by the combined action of heat and a hardening catalyst.

6. The process of delaying the polymerization of liquid phenol formaldehyde which comprises admixing therewith comminuted raw citrus pulp.

7. A composition of matter comprising liquid phenol formaldehyde and an admixture of comminuted raw citrus fruit pulp.

8. A composition of matter comprising the reaction product of one per cent to twenty per cent I-ICl, phenol formaldehyde, comminuted raw citrus pulp insubstantial amount and a solvent for said phenol formaldehyde.

9. A composition of matter comprising the reaction product resulting from polymerization of phenol formaldehyde resin in the presence of comminuted raw citrus pulp.

10. The step in the process of utilizing a member of the group consisting of raw citrus pulp, raw pineapple pulp, raw pineapple leaves, and raw pineapple hulls, which comprises comminuting the pulp ofv said member and mixing the same with liquid phenol formaldehyde resin.

11. The process which comprises comminuting a member of the group consisting of raw citrus pulp, raw pineapple pulp, raw pineapple leaves and raw pineapple hulls, and polymerizing a mixture of said comminuted member and. liquid phenol formaldehyde resin by the combined action of heat and a hardening catalyst.

12. A composition of matter comprising liquid phenol formaldehyde resin and. an admixture of a comminuted member of the group consisting of raw citrus pulp, raw pineapple pulp, raw pineapple leaves and raw pineapple hulls.

13. A composition of matter comprising the reaction product of 1% to 20% E01, liquid phenol formaldehyde resin, a comminuted member of the group consisting of raw citrus pulp, raw pineapple pulp, raw pineapple leaves and raw pineapple hulls in substantial amount, and a solvent for said phenol formaldehyde resin.

OSCAR W. SCI-IROEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,216,728 Pollak Feb. 20, 191'? 2,157,488 I-Iolzcker May 9, 1939 2,280,934 Seebach Apr. 28, 1942 2,319,182 Van der Pyl May 11, 1943 FOREIGN PATENTS Number Country Date 129,993 Great Britain July 16, 1919 OTHER REFERENCES Megson, Jour. Soc. Chem. Ind., June 1938, pp.

Lebach, Jour. Soc. of Chemical Ind., June 16, 1913, pp. 559-563,

Weber, Pacific Plastics, Oct. 1943, vol. 1, Nos. 4 and 5, pages 5, 6, 44, 46. 

